1. Field of the Invention
The present invention relates to an automatic feeding apparatus for feeding articles to an automatic article processing machine, such as a robot, and, particularly, it relates to an automatic feeding apparatus for feeding parts for assembly or interchangeable robot hands to a assembling robot.
2. Description of the Related Art
Recently, rapid advances have been made in automatic assembling techniques and, accordingly, many articles have become manufactured in an automatic assembling system.
With reference to conveying method of products during assembly, the automatic assembling equipment can be classified into a line production system and a non-line production system. The line production system consists of a line for conveying products during assembly and a plurality of automatic assembling machines arranged along said conveying line, as well known in the art. The line production system is mainly used in the process in which large quantity of production and great number of assembling steps are involved and equipment investment can be greatly increased.
The non-line production system is mainly used, for example, when the quantity of production is small, when the product is not adaptable to a conveyor system, when relatively small number of assembling steps are involved, or when it is not preferable to greatly increase the equipment investment.
In case of the automatic assembling equipment according to the line production system, which is frequently used in mass-production system, the speed of conveying products during assembly is high and, consequently, the automatic assembling machines arranged along the assembly line are mainly constructed of high-speed and single-function machines.
On the other hand, in case of the automatic assembling equipment according to the non-line production system, which includes no conveying line for conveying products during assembly or a very short length of such conveying line, if any, the automatic assembling equipment used is frequently constructed of a robot which can effect various kinds of operations. The automatic assembling equipment according to this system has some advantages. That is, many different kinds of products can be assembled by the same equipment if a software used to control the robot is changed, depending upon the product to be assembled, and the floor space occupied by the equipment can be decreased, as compared with the line production system. Accordingly, the automatic assembling equipment according to the non-line production system is suitable to production of small quantity and many kinds of articles. In order to adapt this equipment to production of large quantity and many kinds of articles it is necessary to feed many kinds of parts for assembly to one robot, with the result that it is necessary to arrange great number of feeding apparatus for feeding parts for assembly around said one robot. Accordingly, circumstances surrounding said robot get confused, and the floor space occupied by the equipment and the overall size of the equipment are increased owing to the existence of many feeding apparatus.
As one of the measures for solving such problems, an automatic assembling apparatus has been proposed, which includes carriers movable on conveying paths arranged around an automatic assembling machine, wherein the parts for assembly and/or interchangeable assembling tools are manually loaded on said carriers at remote locations and conveyed into the automatic assembling machine by means of said carriers (see Japanese Laid-Open Utility Model Application No. 4330/1973). In this automatic assembling equipment, it is unnecessary to arrange many feeding apparatus around the automatic assembling machine, so that circumstances surrounding the automatic assembling machine does not get confused and the increase of the overall size of the equipment can be avoided to some extent.
This type of automatic assembling equipment, however, cannot be well adapted to a mixed-flow assembling process for assembling intermediate size and small size lots in which the kinds of products for assembly and the number of assembling steps make successive changes. This is because the loading of the parts for assembly and/or the interchangeable assembling tools onto the carriers requires complicated operation and the working efficiency is considerably decreased. Furthermore, the feeding of the parts for assembly to the automatic assembling machine is effected by the carriers flowing on the conveying paths, so that the working efficiency is low, and the conveying paths require their own floor spaces, so that the overall size of the equipment cannot be decreased beyond a predetermined limit size. This automatic assembling equipment has a further disadvantage in that the parts for assembly are previously set onto the carriers manually in a predetermined process, so that the parts for assembly which have been fed from the respective manufacturing stations must be reloaded onto the carriers in any process, that requires troublesome operations.